Alta825 -
Unfortunately I personally don't have anything to offer relative to your specific vibration concerns (other than I've had u-joints go bad on driveline components, usually in my older muscle cars, and make some pretty whunky noises, perhaps what you're describing...)
However -- with this thread getting revived... I had a question I felt was appropriate to introduce into this discussion about wheel/tire balance.
My curiosity revolves mostly around the challenges in getting a good proper balance on the considerably-sized wheel and tire packages we run on our SMB's...and on the choice of wheel material (alloy vs steel) as well as cosmetic decisions relative to wheel weights.
It certainly
appears that most forum members with well-spec'd rigs (lifted, 4WD) prefer to run a variety of **alloy** wheels (vs. steel.) And, presumably for cosmetic/aesthetic purposes,
you usually don't see many wheel weights visible on the **outside-facing** surfaces of these alloy wheels.
From years of trying to keep my nicely-kept/presented muscle-cars' wheels looking "visually clean / uncluttered" in appearance,
I used to ask the tire shops to only place wheel weights on the **inside edges** of the wheels. They would tell me that there's only so good a balance you can get when you don't allow the tech to place weights on both the extreme inside and outside faces of the rims, but I didn't care for those cars to be 100% perfect, just to look great for car shows and not have ugly wheel weights hanging off the beautifully-painted, color-matched factory steel wheels. (I've had a number of Mopars, and love the body-color steel wheel / dog-dish center cap look.) Since these wheels/tires were so relatively lightweight, and my gearing was so relatively low (car would max revs out before hitting 75mph), freeway vibration wasn't a concern of mine.
But driving the big Sportsmobile now -- and running (at present) 245/75's on 16-inch rims....and traveling at 75-80 mph on California freeways to get to a camping destination....
it's become crucial to get a dead-nuts balance on these big tires. (And I'm going bigger, soon....will be upping to 285/75 series tires (again 16") after the lift kit goes in.)
So I've chosen steel wheels ---- primarily for their ability to take a big wheel weight if necessary, and to mount those wheel weights on the **extreme outside-edges** of both the inside and outside faces of the wheels (aesthetics be damned, I want this van to drive as smooth as possible on these 8-hour drives.)
With alloy wheels, which require stick-on (adhesive-backed) weights, I've seen how oftentimes there isn't the provision to easily mount those weights very close to the outside face of the wheel....or if there is, few people seem to want to have the stick-on weights visible. So usually the wheel weights closest to the outside face of the wheel are still "hidden" or tucked behind the spokes of the wheel, as well.
A less-than-ideal dynamic balance is likely in that situation.
So I guess I'm opening this up to the question: for those with alloy wheels and big tires, how hard has it been to get a quality (and lasting) tire balance on your rigs? And have you ever knowingly accepted a less-than-ideal balance, just to preserve the "clean appearance" (no visible wheel weights) on the outside face of your wheels?